I quit the game and just moved the WARPATCH.BIN file out of my warhammer directory. Then started WAR... VOILA... performance was great again.. BUT then the video flushed after 10 minutes (all textures went blurry and then reloaded) and then performance started to drop alittle.

So... dear devs... there may be something wrong with the Nvidia memory allocations especially on 9 series cards.. when the textures get flushed the game lags like it really isn't flushing the video memory.

Now why IS the video flushing? I am not sure... I have a 1gb video card... maybe this is a bug or something the engine has to do but never seen this in any other game.

Also I notice that changing the shadows setting in game will drop performance and you have to restart to get it back.

If I had to guess, I'd say it's your single-core CPU that's slowing you down. Is it an older P4? A friend of mine with an older CPU (he also has 4 gigs of RAM, and he rolls with a 7950 GX2) also gets slow and choppy framerates.

As mentioned by Jordster the allocation of memory can make a big difference when performance is concerned in online games. His thoughts about a single core CPU in combination with your in-game settings may be causing the effect. You have a decent system that should keep up otherwise. Which CPU model is it specifically? You may want to consider upgrading that component, although if its the model I suspect, you may have to upgrade a few other components, such as the motherboard and memory along with it.

What happens a lot of the times with patches is in-game settings are adjusted by default, new ways of tweaking how things are displayed or converted may change, or any number of other adjustments that may make your previous settings which worked just fine, not work so fine anymore.

Try lower everything in the game settings to minimal, turn off sound, and see how that affects performance.